What is radium-226? For starters, it has a half-life of 1,600 years.

News that a well in the Seminole Improvement District’s water treatment plant exceeded radium-226 drinking water levels made us curious. Some naturally occurring radioactive materials decay rapidly, are easily treated and are not such a big deal.
Others decay very slowly and are more dangerous. So I looked up radium-226 at the U.S. Agency for Toxic Substances Disease Registry. Here’s the info:

It lasts a long, long time:

Radium is a naturally-occurring silvery white radioactive metal that can exist in several forms called isotopes.
One isotope, radium-224 for example, releases half of its radiation in about three and a half days; whereas another isotope, radium-226, releases half of its radiation in about 1,600 years.

When it decays, it produces some relatively harmless radiation products, and some quite troubling ones:

When radium decays it divides into two parts. One part is called radiation, and the second part is called a daughter. The daughter, like radium, is not stable; and it also divides into radiation and another daughter. The dividing continues until a stable, nonradioactive daughter is formed. During the decay process, alpha, beta, and gamma radiations are released. Alpha particles can travel only a short distance and cannot travel through your skin. Beta particles can penetrate through your skin, but they cannot go all the way through your body. Gamma radiation, however, can go all the way through your body.

It can get into your body if you breathe it or swallow it.

Radium can enter the body when it is breathed in or swallowed. It is not known if it can be taken in through the skin. If you breathe radium into your lungs, some may remain there for months; but it will gradually enter the blood stream and be carried to all parts of the body, especially the bones.
For months after exposure, very small amounts leave the body daily through the feces and urine. If radium is swallowed in water or with food, most of it (about 80%) will promptly leave the body in the feces. The other 20% will enter the blood stream and be carried to all parts of the body, especially the bones. Some of this radium will then be excreted in the feces and urine on a daily basis.

It has the potential to cause very serious health effects.

Radium has been shown to cause adverse health effects such as anemia, cataracts, fractured teeth, cancer and death.
Some of these effects may take years to develop and are mostly due to gamma radiation. Radium gives off gamma radiation, which can travel fairly long distances through air. Therefore, just being near radium at the high levels that may be found at some hazardous waste sites may be dangerous to your health.

It was found in raw water at one Seminole Improvement well at 11.1 picocuries per liter. It’s important to note that water goes through treatment before it goes out to customers. But I have no information on the quality of the finished water.
The rest of the wells are being tested, the Florida Department of Health says.

The EPA has set a drinking water limit of 5 picocuries per liter (5 pCi/L) for radium-226 and radium-228 (combined).
The EPA has set a soil concentration limit for radium-226 in uranium and thorium mill tailings of 5 picocuries per gram in the first 15 centimeters of soil and 15 picocuries per gram in deeper soil.